diff --git a/src/Symfony/Component/Serializer/CHANGELOG.md b/src/Symfony/Component/Serializer/CHANGELOG.md
index f2171cb5f4..ab845f736c 100644
--- a/src/Symfony/Component/Serializer/CHANGELOG.md
+++ b/src/Symfony/Component/Serializer/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+5.1.0
+-----
+
+ * added support for scalar values denormalization
+
 5.0.0
 -----
 
@@ -12,7 +17,7 @@ CHANGELOG
    `AbstractNormalizer::$camelizedAttributes`, `AbstractNormalizer::setCircularReferenceLimit()`,
    `AbstractNormalizer::setCircularReferenceHandler()`, `AbstractNormalizer::setCallbacks()` and
    `AbstractNormalizer::setIgnoredAttributes()`, use the default context instead.
- * removed `AbstractObjectNormalizer::$maxDepthHandler` and `AbstractObjectNormalizer::setMaxDepthHandler()`, 
+ * removed `AbstractObjectNormalizer::$maxDepthHandler` and `AbstractObjectNormalizer::setMaxDepthHandler()`,
    use the default context instead.
  * removed `XmlEncoder::setRootNodeName()` & `XmlEncoder::getRootNodeName()`, use the default context instead.
  * removed individual encoders/normalizers options as constructor arguments.
diff --git a/src/Symfony/Component/Serializer/Serializer.php b/src/Symfony/Component/Serializer/Serializer.php
index ee2c750179..8dc1faf5de 100644
--- a/src/Symfony/Component/Serializer/Serializer.php
+++ b/src/Symfony/Component/Serializer/Serializer.php
@@ -46,6 +46,13 @@ use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
  */
 class Serializer implements SerializerInterface, ContextAwareNormalizerInterface, ContextAwareDenormalizerInterface, ContextAwareEncoderInterface, ContextAwareDecoderInterface
 {
+    private const SCALAR_TYPES = [
+        'int' => true,
+        'bool' => true,
+        'float' => true,
+        'string' => true,
+    ];
+
     /**
      * @var Encoder\ChainEncoder
      */
@@ -177,6 +184,14 @@ class Serializer implements SerializerInterface, ContextAwareNormalizerInterface
      */
     public function denormalize($data, string $type, string $format = null, array $context = [])
     {
+        if (isset(self::SCALAR_TYPES[$type])) {
+            if (!('is_'.$type)($data)) {
+                throw new NotNormalizableValueException(sprintf('Data expected to be of type "%s" ("%s" given)', $type, \is_object($data) ? \get_class($data) : \gettype($data)));
+            }
+
+            return $data;
+        }
+
         if (!$this->normalizers) {
             throw new LogicException('You must register at least one normalizer to be able to denormalize objects.');
         }
@@ -201,7 +216,7 @@ class Serializer implements SerializerInterface, ContextAwareNormalizerInterface
      */
     public function supportsDenormalization($data, string $type, string $format = null, array $context = [])
     {
-        return null !== $this->getDenormalizer($data, $type, $format, $context);
+        return isset(self::SCALAR_TYPES[$type]) || null !== $this->getDenormalizer($data, $type, $format, $context);
     }
 
     /**
diff --git a/src/Symfony/Component/Serializer/Tests/SerializerTest.php b/src/Symfony/Component/Serializer/Tests/SerializerTest.php
index 4852721539..a60c81322f 100644
--- a/src/Symfony/Component/Serializer/Tests/SerializerTest.php
+++ b/src/Symfony/Component/Serializer/Tests/SerializerTest.php
@@ -17,6 +17,7 @@ use Symfony\Component\PropertyInfo\Extractor\PhpDocExtractor;
 use Symfony\Component\PropertyInfo\Extractor\ReflectionExtractor;
 use Symfony\Component\Serializer\Encoder\JsonEncoder;
 use Symfony\Component\Serializer\Exception\InvalidArgumentException;
+use Symfony\Component\Serializer\Exception\LogicException;
 use Symfony\Component\Serializer\Exception\NotNormalizableValueException;
 use Symfony\Component\Serializer\Mapping\ClassDiscriminatorFromClassMetadata;
 use Symfony\Component\Serializer\Mapping\ClassDiscriminatorMapping;
@@ -488,6 +489,86 @@ class SerializerTest extends TestCase
         (new Serializer())->normalize(tmpfile());
     }
 
+    public function testNormalizeScalar()
+    {
+        $serializer = new Serializer([], ['json' => new JsonEncoder()]);
+
+        $this->assertSame('42', $serializer->serialize(42, 'json'));
+        $this->assertSame('true', $serializer->serialize(true, 'json'));
+        $this->assertSame('false', $serializer->serialize(false, 'json'));
+        $this->assertSame('3.14', $serializer->serialize(3.14, 'json'));
+        $this->assertSame('3.14', $serializer->serialize(31.4e-1, 'json'));
+        $this->assertSame('"  spaces  "', $serializer->serialize('  spaces  ', 'json'));
+        $this->assertSame('"@Ca$e%"', $serializer->serialize('@Ca$e%', 'json'));
+    }
+
+    public function testNormalizeScalarArray()
+    {
+        $serializer = new Serializer([], ['json' => new JsonEncoder()]);
+
+        $this->assertSame('[42]', $serializer->serialize([42], 'json'));
+        $this->assertSame('[true,false]', $serializer->serialize([true, false], 'json'));
+        $this->assertSame('[3.14,3.24]', $serializer->serialize([3.14, 32.4e-1], 'json'));
+        $this->assertSame('["  spaces  ","@Ca$e%"]', $serializer->serialize(['  spaces  ', '@Ca$e%'], 'json'));
+    }
+
+    public function testDeserializeScalar()
+    {
+        $serializer = new Serializer([], ['json' => new JsonEncoder()]);
+
+        $this->assertSame(42, $serializer->deserialize('42', 'int', 'json'));
+        $this->assertTrue($serializer->deserialize('true', 'bool', 'json'));
+        $this->assertSame(3.14, $serializer->deserialize('3.14', 'float', 'json'));
+        $this->assertSame(3.14, $serializer->deserialize('31.4e-1', 'float', 'json'));
+        $this->assertSame('  spaces  ', $serializer->deserialize('"  spaces  "', 'string', 'json'));
+        $this->assertSame('@Ca$e%', $serializer->deserialize('"@Ca$e%"', 'string', 'json'));
+    }
+
+    public function testDeserializeLegacyScalarType()
+    {
+        $this->expectException(LogicException::class);
+        $serializer = new Serializer([], ['json' => new JsonEncoder()]);
+        $serializer->deserialize('42', 'integer', 'json');
+    }
+
+    public function testDeserializeScalarTypeToCustomType()
+    {
+        $this->expectException(LogicException::class);
+        $serializer = new Serializer([], ['json' => new JsonEncoder()]);
+        $serializer->deserialize('"something"', Foo::class, 'json');
+    }
+
+    public function testDeserializeNonscalarTypeToScalar()
+    {
+        $this->expectException(NotNormalizableValueException::class);
+        $serializer = new Serializer([], ['json' => new JsonEncoder()]);
+        $serializer->deserialize('{"foo":true}', 'string', 'json');
+    }
+
+    public function testDeserializeInconsistentScalarType()
+    {
+        $this->expectException(NotNormalizableValueException::class);
+        $serializer = new Serializer([], ['json' => new JsonEncoder()]);
+        $serializer->deserialize('"42"', 'int', 'json');
+    }
+
+    public function testDeserializeScalarArray()
+    {
+        $serializer = new Serializer([new ArrayDenormalizer()], ['json' => new JsonEncoder()]);
+
+        $this->assertSame([42], $serializer->deserialize('[42]', 'int[]', 'json'));
+        $this->assertSame([true, false], $serializer->deserialize('[true,false]', 'bool[]', 'json'));
+        $this->assertSame([3.14, 3.24], $serializer->deserialize('[3.14,32.4e-1]', 'float[]', 'json'));
+        $this->assertSame(['  spaces  ', '@Ca$e%'], $serializer->deserialize('["  spaces  ","@Ca$e%"]', 'string[]', 'json'));
+    }
+
+    public function testDeserializeInconsistentScalarArray()
+    {
+        $this->expectException(NotNormalizableValueException::class);
+        $serializer = new Serializer([new ArrayDenormalizer()], ['json' => new JsonEncoder()]);
+        $serializer->deserialize('["42"]', 'int[]', 'json');
+    }
+
     private function serializerWithClassDiscriminator()
     {
         $classMetadataFactory = new ClassMetadataFactory(new AnnotationLoader(new AnnotationReader()));